package com.hmdp.utils;

import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;

import javax.annotation.Resource;
import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;

@Component
public class RedisIdWorker {

    @Resource
    private StringRedisTemplate  stringRedisTemplate;

    public RedisIdWorker(StringRedisTemplate stringRedisTemplate) {
        this.stringRedisTemplate = stringRedisTemplate;
    }

    private static final long BEGIN_TIMESTAMP = 1640995200L;//  2022-01-01 00:00:00

    private static final int COUNT_BITS = 32;
    /*
    * 生成唯一id
    * */
    public Long nextId(String keyPrefix) {
        // 1.生成时间戳
        LocalDateTime now = LocalDateTime.now();
        long nowSecond = now.toEpochSecond(ZoneOffset.UTC);//  获取秒级时间戳
        long timeStamp = nowSecond  - BEGIN_TIMESTAMP;
        // 2.生成序列号
        String date = now.format(DateTimeFormatter.ofPattern("yyyy:MM:dd"));
        long count = stringRedisTemplate.opsForValue().increment("icr:" + keyPrefix + ":" + date);//  获取自增序列号
        return timeStamp << COUNT_BITS | count;
    }
}
